futaba 8 channel
 

i recently aquired a 8 channel futaba transmitter. it is on freq. #60. all my other radios and planes are on #38 i know i am not supposed to switch crystals. but when i tried it in my shop at home just to see if everything worked ok, nothing happened. shouldnt the transmitter at least move the controls on my planes . i am not going to fly anything with this without sending it to futaba, just wanted to make sure it was working. thanks in advance for any help.

RE: futaba 8 channel
 

Make sure that the TX is transmitting the appropriate signal PPM or PCM ;)
Been there done that !

RE: futaba 8 channel
 

i have tried that in both modes, still nothing.

RE: futaba 8 channel
 

If your other receivers are Futaba I would bet that the 8 is not working. Swapping crystals shouldn't make that big a difference that close. Are your other radios also Futaba.

RE: futaba 8 channel
 

yes, all my other radios are futaba. the transmitter comes on and the screen shows the amount of charge etc. it also lets you program your planes into it.

RE: futaba 8 channel
 

What receiver are you using?
Also the 8U and 8U's doesn't have a crystal.
So what exactly did you change on the transmitter?

RE: futaba 8 channel
 

The 8 U has a crystal in the module. You can change that.

RE: futaba 8 channel
 

The last time i ordered a pcm receiver for one of 8uap transmitters , I had to specify wether it was a high or low frequency transmitter to get a matching reciever . The split between high and low is somewhere between channels 30 and 40. If you have a high frequency transmitter you
wount be able to use a low frequency reciever or swap high and low frequency crystals .It is my understanding (and i am no expert) that the
recievers are tuned at either high or low for better modulation control . Some of the experts may have a better explaination .

RE: futaba 8 channel
 

If is is a 148dp it is pcm if it is a 148df it is ppm. After you switch modes you must turn the radio off and on to reset the signal. You can change your rx from 60 to 38, they are both high band. Don't change the crystal in your module.

RE: futaba 8 channel
 

are you guys saying i need to use a special receiver for this transmitter. i am trying to use the transmitter that came with my 6 channel futaba transmitter. i think it is a rf127 or something like that. also i removed the module from the back of the 8 and there is a crystal in there that i changed.?????

RE: futaba 8 channel
 

It looks ike there is a problem with the transmitter. It should work with that receicer. Using the ppm mode. Some of the early models of the 8U had problems with the pins were the module pluged in.Causing no rf output.

RE: futaba 8 channel
 

If your transmitter was originally on channel 60, and you changed the crystal to channel 38, it's possible that the transmitter is now out of tune enough that the receiver's not getting a good signal. To clarify, your transmitter module may need to be tuned...or it's the receiver that's off, and you'll need to get it and its transmitter tuned. Without putting them on the proper test equipment, there's no telling what might be wrong.

Any Futaba FM-PPM receiver will work with any Futaba FM-PPM transmitter. Any Futaba PCM1024 receiver will work with your 8U-series transmitter. The Futaba R127DF is an FM-PPM receiver, so you'll have to make sure that your transmitter is transmitting in PPM mode.

RE: futaba 8 channel
 

well, thank you to everyone who helped. i got the transmitter in the proper mode, with the proper crystal, and everything worked great. now if i can just figure out all the different programs. i guess it wont be too bad. i bought this at a swap meet for $80 so i guess i did ok. well its off to futaba now for the crystal change, and a tune up. thanks again to everyone who helped.